DEMO MANUAL DC2310A
LTC5549
2GHz to 14GHz Passive
Bidirectional Mixer
aBsoLute MaxiMuM input
ratings
Supply Voltage (V
CC
) ..................................................4V
Enable Input Voltage (EN) ................–0.3V to V
CC
+ 0.3V
LO Input Power (1GHz to 12GHz) ....................... +10dBm
LO Input DC Voltage............................................... ±0.1V
RF Input Power (2GHz to 14GHz) .......................+20dBm
RF Input DC Voltage ............................................... ±0.1V
IF Input Power (0.5GHz to 6GHz) .......................+20dBm
IF Input DC Voltage ................................................ ±0.1V
Operating Temperature Range (T
C
) ........ –40°C to 105°C
Junction Temperature (T
J
) .................................... 150°C
Storage Temperature Range .................. –65°C to 150°C
CAUTION: This part is sensitive to electrostatic discharge
(ESD). Observe proper ESD precautions when handling
the LTC5549.
Description
Demonstration circuit 2310A is optimized for evaluation
of the
LTC
®
5549
passive double-balanced mixer with
integrated LO frequency doubler. Its RF port is matched
to 50Ω from 2GHz to 13.6GHz with 9dB return loss, and
the LO port is matched to 50Ω from 1GHz to 12GHz with
10dB return loss. The IF output is matched to 50Ω from
700MHz to 6GHz with 10dB return loss. The LTC5549 can
be used for upconverting and downconverting applications.
The internal LO doubler can be enabled to allow operation
with a lower frequency LO input signal such as that from
the
LTC6945/LTC6946
or
LTC6947/LTC6948
family of
frequency synthesizers.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2310A
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
BoarD Layout
Figure 1. DC2310A
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DEMO MANUAL DC2310A
proper test setups
Figure 2. Test Setup for Downconverting Mixer 2-Tone Measurements
Figure 3. Test Setup for Upconverting Mixer 2-Tone Measurements
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DEMO MANUAL DC2310A
notes on test eQuipMent anD setup
•
High performance signal generators with low harmonic
outputs should be used for 2-tone measurements. Oth-
erwise, low pass filters at the signal generator outputs
should be used to suppress harmonics.
•
High quality combiners should be used to present a
broadband 50Ω termination on all ports as well as
provide good port-to-port isolation. Adding attenuator
pads further improves source isolation and helps prevent
the signal generators from producing intermodulation
products.
•
Spectrum analyzers can produce significant internal
distortion products if they are overdriven. Generally,
spectrum analyzers are designed to operate at their
best with about –30dBm to –40dBm at their input. The
spectrum analyzer’s input attenuation setting should
be used to avoid saturating the instrument.
•
Set the spectrum analyzer’s input attenuation depending
on the spectrum analyzer used.
•
Before performing measurements on the DUT, the
system performance should be evaluated to ensure that
a clean input signal is obtained and that the spectrum
analyzer’s internal distortion is minimized.
Quick start proceDure
1. Connect all test equipment as shown in Figure 2.
2. Set the power supply output voltage to 3.3V, and set
the current limit to 200mA.
3. Connect the ground and V
CC
turrets to the power sup-
ply.
BE SURE TO CONNECT THE V
CC
TURRET
BEFORE
THE EN TURRET TO ENSURE THAT THE PART DOES
NOT GET DAMAGED. ALSO, REMOVE POWER FROM
EN TURRET
BEFORE
REMOVING POWER FROM THE
V
CC
TURRET.
4. Connect the EN turret to the power supply.
5. Set the LO signal generator to provide a 3910MHz CW
signal at about 0dBm to the demo board’s LO port.
6. Set the RF signal generators to provide one 5799MHz
CW signal and one 5801MHz CW signal. The signals
should be applied to the 2-way combiner. The output
of the combiner should be applied to the demo board’s
RF input port. The two tones should be set to –5dBm
each at the mixer’s RF input port.
7. Set the spectrum analyzer’s center frequency to
1890GHz.
8. Perform various measurements
(Conversion Gain, OIP3, LO leakage, etc.)
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DEMO MANUAL DC2310A
parts List
ITEM
1
2
3
4
5
6
QTY
2
1
2
4
3
1
REFERENCE
C1, C4
C2, C5
C3
E1 to E4
J1 to J3
U1
PART DESCRIPTION
CAP, 0.15pF,100V, ±0.01pF, 0402
CAP, 22pF, C0G, 50V, 5%, 0402
CAP, 1µF, X7R, 10V, 10%, 0603
TEST POINT, TURRET, 0.061" MTG HOLE
CONN, SMA 50Ω EDGE-LAUNCH
IC LTC5549IUDB, QFN 12 PIN, 3mm × 2mm
MANUFACTURER/PART NUMBER
AVX, 04021JR15ZBS
AVX, 04025A220JAT2A
AVX, 0603ZD105KAT2A
MILL-MAX, 2308-2-00-80-00-00-07-0
EF JOHNS ON, 142-0701-851
LINEAR TECHNOLOGY, LTC5549IUDB#PBF
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DEMO MANUAL DC2310A
DeMo BoarD scheMatic
Figure 4. DC2310A Schematic
dc2310af
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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